caliber302003

Hi Guys
Im looking to put rudders on my hotspot that im busy refurbing. Could the guys that have done this - chime in and give me some help.

Im ready to cut the rudder out of the 2 fins and also cut the servo holes - now do i use a slim line servo from hitec (HS-5125) which only has 49oz of torque, is this enough??
Or should i use a standard size servo and build the aera up to create a nice smooth incline from the fin to the tops of the rudder?


Any picture and help would be greatly appreciated !

Gary Arthur

My Feedback: (29)

I used a Wingmaxx HP servo in my rudders. They are slim and fit inside.

caliber302003

Cheers Gary do you have a link to them?

Gary Arthur

My Feedback: (29)

[link=http://www.soaringusa.com/products/product.htm?product_id=16479&category_id=269]http://www.soaringusa.com/products/product.htm?product_id=16479&category_id=269[/link]

Be sure to by the metal arms.

Woketman

My Feedback: (6)

I did this many years ago. I made the rudders constant chord, full height, and about 1.75 to 2 inches in width (chord), IIRC.

I used standard sized (full sized) MPX servos, probably about 60 oz-in. I cut a hole in the verticals, just above the fuselage, and let the body of the servos poke all the way through. I reinforced the top side of each opening with a piece of 1/8" aircraft ply, epoxied on, and that is what the hold down screws were screwed into. I think I had the servo tops outboard, but I could be wrong. It worked great, never an issue. Sorry, I am traveling and have no photos available right now.

erbroens

49 oz/in is plenty.. just be sure to use the proper geometry in the linkages . I always had the rudder servos in the fuselage in this plane, including the fast one.


Enrique

Kelly W

My Feedback: (2)

I'd also throw my vote in for the Wing Maxx servos. Mine are the non-HP version and I used the stock plastic arm. Another local Hotspot owner went the route of the Hitec thin servos and has experienced several stripped gear trains in normal flight. He wasn't flying particularly fast or aggressively either. I'm OK with using Hitecs in general, but based on that I would stay away from the HS 125 or 5125 in this application.

Also, don't cut the rudder full length of the fins trailing edge. Its not necessary and leaving the tip complete will tend to stabilize the airflow (avoiding flutter). The chord of the rudder is a simple trade off of rudder control vs fin stiffness, which I would error towards the stiffness if you want to go fast. I've included a few photos of my rudder geometry. I've gone passed 250 mph with it several times.

Kelly

Gary Arthur

My Feedback: (29)

My rudders are identical to Kelly's. Same servos, same cut out style, same covers. Works fine.....

cmjets

Hi Caliber:

I had in my Hotspots Hitec HS5125MG and fit pertect and run perfect and are enough for the ruders of this model.

And you will get a perfect finish in the 10mm vertical fin with this servos of 10mm.

Regards from Spain.


Visit my Blog:

http://cmjets.blogspot.com/

caliber302003

Awesome guys thanks very much for the information. anyone got any pics of the internals? im new to jets so pics of the internals will help me alot for placment of the hardware

Kevin Greene

My Feedback: (85)

Ditto with using this servo....No problems at all with this metal gear servo...

Kevin

lov2flyrc

My Feedback: (24)

I used the Volz servos on my Kangaroo (before the JR DS-168 or Hitec HS125 were available) and did not have much luck with them. Went through three sets over the course of 2 years. The would just stop working for no appearant reason [] Eventually swapped them for the DS-168 and never had another problem....

Woketman

My Feedback: (6)

Now that I see those photos, I do not think mine were full height. I had a fin tip on there too.